A new study of the spectroscopic binary 7 Vul with a Be star primary

Autor(es)

Harmanec, P. ^[1] ; Liptak, J. ^[1] ; Koubsky, P. ^[2] ; Bozic, H. ^[3] ; Labadie-Bartz, J. ^[4] ; Slechta, M. ^[2] ; Yang, S. ^[5] ; Harmanec, A. ^[6]

Afiliação do(s) autor(es)

^[1] Charles Univ Prague, Astron Inst, Fac Math & Phys, Holesovickach 2, Prague 18000 8 - Czech Republic

^[2] Acad Sci, Astron Inst, Fricova 298, Ondrejov 25165 - Czech Republic

^[3] Zagreb Univ, Fac Geodesy, Hvar Observ, Kaciceva 26, Zagreb 10000 - Croatia

^[4] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, Cidade Univ, BR-05508900 Sao Paulo, SP - Brazil

^[5] Univ Victoria, Phys & Astron Dept, POB 3055 STN CSC, Victoria, BC V8W 3P6 - Canada

^[6] Charles Univ Prague, Fac Math & Phys, Holesovickach 2, Prague 18000 8 - Czech Republic

• Tipo de documento: Artigo Científico
• Fonte: Astronomy & Astrophysics; v. 639, JUL 3 2020.
• Citações Web of Science: 0

Resumo

We confirmed the binary nature of the Be star 7 Vul, derived a more accurate spectroscopic orbit with an orbital period of 69(.)(d)4212 +/- 0(.)(d)0034 69 . d 4212 +/- 0 . d 0034 , and improved the knowledge of the basic physical elements of the system. Analyzing available photometry and the strength of the H alpha emission, we also document the long-term spectral variations of the Be primary. In addition, we confirmed rapid light changes with a period of 0(.)(d)5592 0 . d 5592 , which is comparable to the expected rotational period of the Be primary, but note that its amplitude and possibly its period vary with time. We were able to disentangle only the HeI 6678 angstrom line of the secondary, which could support our tentative conclusion that the secondary appears to be a hot subdwarf. A search for this object in high-dispersion far-UV spectra could provide confirmation. Probable masses of the binary components are (6 +/- 1) ?(N)(circle dot) M circle dot N and (0.6 +/- 0.1) ?(N)(circle dot) M circle dot N . If the presence of a hot subdwarf is firmly confirmed, 7 Vul might be identified as a rare object with a B4-B5 primary; all Be + hot subdwarf systems found so far contain B0-B3 primaries. (AU)

• Processo FAPESP: 17/23731-1 - Análise e Modelagem de uma Grande Amostra de Estrelas Be Galácticas
• Beneficiário: Jonathan Michael Labadie-Bartz
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado